The present invention relates to a charging system for an internal combustion engine of a vehicle, particularly to an alternating current (a.c.) generator control system for a vehicle generator driven by the internal combustion engine to generate electric power.
Conventional a.c. generators driven by an internal combustion engine of an automobile are commonly controlled by a controller called an IC regulator, which detects and controls the voltage of a vehicle battery charged by the generator. Japanese Patent Laid-Open No. 161195/1985 discloses a vehicle alternating current generator controller which uses a microcomputer to systematically and smoothly control electric-power generation according not only to the state of vehicle battery, but also the states of the engine and the electric load. The controller receives a signal indicative of an operating parameter of the internal combustion engine, such as from a sensor for detecting a turned-on air conditioner or headlamp, to detect the state of operation or electric load, and voltages generated by the generator are switched in response to the vehicle operational state or electric load state.
For the above generator controller according to the prior art, it is possible to achieve smoother control of generator operation by taking into account an operational state of the vehicle, or its electric-load state. However, even though this prior art system can achieve adequate fuel efficiency and power performance, it does not maintain stable operation because target or command voltages are determined only by the controller itself, and no correction is made.